Electric switch with roller and ball contact structure



Dec. 27, 1966 D. w. JOHNSON 3,294,929

'ELECTRIC SWITCH WITH ROLLER AND BALL CONTACT STRUCTURE Filed Sept. 5, 1965 INVENTOR.

Dav/'0 W Johnson BY MS al/omeys Mam/M United States Patent ELECTRIC SWITCH WITH ROLLER AND BALL CONTACT STRUCTURE David W. Johnson, Newington, Conn., assignor to The Arrow-Hart & Hegeman Electric Company, Hartford, Conn., a corporation of Connecticut Filed Sept. 3, 1965, Ser. No. 485,016 6 Claims. (Cl. 200-11) This invention relates to rotary switches of the type in which one or more centrally located contacts are selectively connected to peripheral contacts by means of movable bridging members. In particular this invention relates to a rotary switch of the type described in which certain bridging members are effective to electrically connect only certain of the peripheral contacts to the central contact or contacts, thus permitting a more diverse choice in the combination of circuits which can be provided.

In United States Patent No. 2,817,722, of the present inventor there is described a rotary switch comprising two inner or central contacts, and a larger number of outer or peripheral contacts. A rotary member carrying a number of balls, is provided and depending on the position of this rotary member, the balls will bridge the gap between a peripheral contact and a central contact establishing a circuit for that peripheral contact. Depending on the number of balls provided, several circuits may be completed with each setting of the rotary member. For some applications, however, it may be desired to have a circuit completed by a certain one of the bridging or connecting elements only for a certain setting of the rotary member and in no other case.

It is therefore an object of the invention to provide, in a rotary switch having one or more central contacts, a plurality of peripheral contacts and a rotary member containing a plurality of bridging members, means for insuring that a circuit will be completed by one of said bridging members only in a selected position of said rotary member.

It is another object of the invention to provide in a switch of the class described, means for increasing the flexibility of the switch by increasing the number of combinations of contact connections which can be made available.

Other objects will become clear from a consideration of the following specification and claims.

In accordance with the invention, the enumerated and other objects are attained by means of an electric switch comprising an insulating carrier plate, a plurality of central fixed contacts, a plurality of peripheral fixed contacts located in a circle about said central contacts, a rotary member, a first class of resiliently supported connecting members, each of said first class of connecting members being adapted to bridge a central fixed contact and an adjacent peripheral fixed contact, in combination with at least one of a second class of resiliently supported connecting members, of different shape from the connecting members of the first class and means for insulating said second class members from certain of said peripheral contacts, said insulating means being ineffective so to insulate connecting members of the first class.

The invention will be further described with reference to the accompanying drawings in which FIG. 1 is an exploded view of a rotary switch according to the invention.

FIG. 2 is a plan view of a contact carrying disc in the switch of FIG. 1, the view being taken from the reverse side as compared to the showing of this disc in FIG. 1.

FIG. 3 is a view in vertical section of a switch according to the invention, the view corresponding to the secti-on 35 of FIG. 2, the retaining means being omitted for clarity.

Referring to the drawing, a switch according to the invention comprises a disc-like fixed contact carrier 10 and a handle 11. The carrier 10 comprises a metallic mounting plate 12 which may have holes such as 13 to enable it to be mounted, for example on a panel, not shown. The mounting plate has a large central aperture 14 around the periphery of which there extend radially inwardly a plurality of square lugs 15. Two of these, 15a and 151) are bent at right angles to the plate 12 to form stops whose function is more fully described below.

On the surface of the plate 12 opposite to that toward which the lugs 15a and 15b are bent is fixed an insulation plate 16. As shown in FIG. 1, this plate has a large central aperture 17 which is, however, substantially smaller than the aperture 14 in the plate 12.

On the interior edge of the insulation plate 16 which defines the aperture 17, is a square notch 18.

Directly on top of the plate 16 is mounted a packing washer 19 which may be stamped from a sheet of insulating material. This washer has a central aperture 20 which is approximately the same size as the aperture 14 in the plate 12. Two tabs 21, 22, having small apertures 21a and 22a, project radially inwardly from the washer 19. Their function will be explained more fully below.

On top of the washer 19 is placed a contact disc 23. This disc, which is also made of an insulating material, has a small central aperture 24. Outwardly from the central aperture 24 are two diametrically opposed slots 25, 26. Further out still is a ring of D-shaped semi-circular apertures 27 and beyond them a ring of slots 28. As shown in FIG. 2, two central contact and terminal members 29, 30 are fixed to the side of the disc 23 nearest plate 12, on opposite sides of the aperture 24. These members comprise arcuate sections 31, 32 and terminal prongs 33, 34 extending in a direction normal to the arcuate sections 31, 32. The arcuate sections 31, 32 have a plurality of pointed radial extensions such as 35, which, in general, lie between the semi-circular apertures 27 and are bent slightly away from the disc 23 to form hollows centering on the apertures.

Associated with the semi-circular apertures 27 and the corresponding slots 28 are a series of peripheral contact members 36. These are, in general, of the same construction as shown in Patent 2,817,722. They comprise a central flat part 37 (FIG. 3) adapted to lie on the surface of disc 23 with one end bent to form a finger 38 which enters the semi-circular aperture 27. The opposite end is bent to form a terminal prong 39 which extends through the corresponding slot 28. If desired, certain of these peripheral contacts may be made in double or triple form as disclosed in said Patent 2,817,722.

The elements 12, 16, 19 and 23 are all fastened together, as by rivets, to provide the fixed contact carrier 10, which may then be assembled, as shown in FIG. 1 to the handle 11 by means of a bolt 40, sleeves 41, 42 and 43 which fit through the central aperture in the disc 23, and a corresponding aperture 44 in handle 11, washer 45 and nut 46.

The face of fixed contact carrier 10 which faces the handle 11 is shown in FIG. 2. As shown in that figure, each hollow or space between any two adjacent points 35 of the central contacts 29, 30 is confronted by one of the bent fingers 38 of a peripheral contact member 36. (See also FIG. 3.) It will further be observed that a substantial part of the fiat central portion 37a of one (36a) of the contact members 36 is exposed by reason of the notch 18 in the insulating plate 16 being positioned over said member 36a. The central portions 37 of the remaining contact members 36 are substantially screened by the plate 16.

The tabs 21 and 22 of washer 19 are arranged to surround those semi-circular holes in which there is no peripheral contact. They also fill in the space between the arcuate sections of the central contacts and provide smooth operation of the switch.

Turning now to the handle 11, this comprises a plurality of recesses 47 arranged in a circle about a central aperture 44. All but one of these recesses are circular in cross-section and contain coiled compression springs 48, and stamped metal caps 49 which are pressed against spherical movable contact members 50.

A valuable and distinguishing feature of the invention resides in providing one recess, 47a, having a rectangular cross-section and also providing a cylindrical contact member 51 for sliding movement in that rectangular recess. This cylindrical contact is spring-biased like the balls 50.

In the assembled switch the presence of a contact ball 50 in a hollow or space between any two points of one of the central fixed contact members (29 or 30) and a confronting peripheral contact 36, will establish an electrical connection between the central contact and the peripheral contact. The combination of circuits which may be established for any position of the handle 11, will depend upon the number and position of the spherical contacts in the handle and upon the cylindrical contact 51. However, the latter can only establish contact with fixed contact 36a which overlies notch 18 in the insulating plate 16. The cylindrical contact 51 is dimensioned to fit into that notch and to contact the flat central portion of the peripheral contact 36a and connect it to the inner or central contact 29. The cylindrical contact 51 is ineffective to engage any other peripheral contact because as the handle is turned the cylindrical contact rides up on and over the surface of the insulating plate 16 and thus is held out of contact with the central portion 37 of the peripheral contact 36.

The switch is assembled with the bent lugs a, 15b seated in a track 52 around the periphery of the handle 11. This track has a block 53 which cooperates with the lugs 15a, 15b to limit rotation of the handle relative to the fixed contact carrier.

Thus, the present invention provides a rotary switch of the class described which is very adaptable with respect to the number of difierent circuit arrangements with which it can be used. By varying the number of fixed contacts, both inner and outer, and by varying the number of contact balls, the invention may be used in connection with a large number of circuit arrangements.

Also, although only one notch is shown in the insulating plates 16, in the embodiment described, this can be varied as to both position and number. Similarly, although only one roller is used, obviously a plurality of rollers may be employed.

The invention thus provides advantages and usages not envisaged by any prior switches of similar nature.

Modifications within the scope of the invention will occur to those familiar with the art. Therefore, the invention is not limited to the specific form illustrated and described.

What is claimed is:

1. A rotary electric switch comprising an insulating carrier plate having a plurality of circularly arranged apertures, a plurality of central fixed contacts arranged adjacent the inner edges of said apertures, a plurality of peripheral fixed contact members adjacent the outer edges of said apertures, a manually operable rotary member, a first class of one or more resiliently supported connecting members carried by said rotary member, each of said connecting members being adapted to bridge a central fixed contact and a peripheral contact, in combination with a second resiliently supported connecting member, said second member being different geometrically from connecting members of the first class, and means for insulating said second connecting member from certain but not from all of said fixed contacts as said rotary member is rotated, said insulating means being inoperative to insulate said first class of connecting members from any of said fixed contacts.

2. The switch claimed in claim 1 wherein the connecting members of the first class are balls and the second connecting member is a cylinder having an axial dimension greater than the diameter of the balls.

3. The switch claimed in claim 4 wherein the insulating means comprises an insulating ring covering a portion of certain of the contacts of one set and leaving a portion exposed, said ring having a cut out section exposing a portion of one of the contacts of said one set more extensive than the exposed portion of said certain contacts.

4. A rotary electric switch comprising an insulating carrier plate, a plurality of central fixed contacts comprising a first set of contacts, a plurality of peripheral fixed contacts located in a circle about said central fixed contacts and comprising a second set of contacts, a manually operated rotary member, a first class of one or more resiliently supported connecting members, each connecting member of said first class being adapted to connect a peripheral contact with a central contact, in combination with a second resiliently supported connecting member, said second member being of diflerent shape from the connecting members of the first class and means for insulating said second member from some but not all of the contacts of one of said sets.

5. The switch claimed in claim 4 wherein the first class of connecting members are balls and the second connecting member is a cylinder.

6. A rotary switch comprising a mounting plate having an aperture, a contact disc secured to one side of said mounting plate, and an insulating ring interposed between said mounting plate and said contact disc, said contact disc having a plurality of peripheral contacts circularly disposed and a plurality of central contacts, said insulating disc covering a major portion of all but one of said peripheral contacts, in combination with a handle rotatable with respect to said plate and having spring loaded balls adapted to bridge said central and peripheral contacts, and at least one spring loaded cylinder effective to bridge a central contact and said one peripheral contact, but no other peripheral contact.

References Cited by the Examiner UNITED STATES PATENTS 12/1957 Johnson 200- 5/1958 Le Beau 200-65 X 

1. A ROTARY ELECTRIC MEANS COMPRISING AN INSULATING CARRIER PLATE HAVING A PLURALITY OF CIRCULARLY ARRANGED APERTURES, A PLURALITY OF CENTRAL FIXED CONTACTS ARRANGED ADJACENT THE INNER EDGES OF SAID APERTURES, A PLURALITY OF PERIPHERAL FIXED CONTACT MEMBERS ADJACENT THE OUTER EDGES OF SAID APERTURES, A MANUALLY OPERABLE ROTARY MEMBER, A FIRST CLASS OF ONE OR MORE RESILIENTLY SUPPORTED CONNECTING MEMBERS CARRIED BY SAID ROTARY MEMBER, EACH OF SAID CONNECTING MEMBERS BEING ADAPTED TO BRIDGE A CENTRAL FIXED CONTACT AND A PERIPHERAL CONTACT, IN COMBINATION WITH A SECOND RESILIENTLY SUPPORTED CONNECTING MEMBER, SAID SECOND MEMBER BEING DIFFERENT GEOMETRICALLY FROM CONNECTING MEMBERS OF THE FIRST CLASS, AND MEANS FOR INSULATING SAID SECOND CONNECTING MEMBER FOR CERTAIN BUT NOT FROM ALL OF SAID FIXED CONTACTS AS SAID ROTARY MEMBER IS ROTATED, SAID INSULATING MEANS BEING INOPERATIVE TO INSULATE SAID FIRST CLASS OF CONNECTING MEMBERS FROM ANY OF SAID FIXED CONTACTS. 